Automatic deep fat fryer

ABSTRACT

Apparatus for automatically frying potato pieces in a hot oil bath. The apparatus is arranged to receive french fry type potato pieces, subject the pieces to a pre-determined interval of cooking in a hot oil bath, thereafter allow the pieces to drain of excess hot oil and transfer the drained pieces to a holding basket for subsequent distribution. A process for automatically preparing french fries including the steps of subjecting french fry shaped pieces of potato dough to a pre-determined term of cooking in a hot oil while tumbling the pieces to insure uniform contact with the hot oil and thereafter draining any excess oil therefrom prior to transferring the drained cooked dough pieces to a holding area.

United States Patent 1 1 Veeneman et al.

1111 3,776,126 1451 Dec. 4, 1973 AUTOMATIC DEEP FAT FRYER [75]Inventors: John L. Veeneman; Marion E.

Thomas; Harry R. Deveraux, all of Idaho Falls, Idaho [73] Assignee:American Potato Company, San

Francisco, Calif.

[22] Filed: May 8, 1972 [21] Appl. No.: 251,611

[52] US. Cl 99/404, 99/353, 99/407,

99/408, 99/443 C, 425/311 [51] Int. Cl. A47j 37/12 [58] Field of Search99/443 6, 404, 407, 99/408, 353

[56] References Cited UNITED STATES PATENTS 1,789,428 1 1931 Descheneset al. 99 407 3,695,171 10 1972 Hartley et al. 99 404 3,474,726 10 19 9Curtin 99 404 2,050,475 8/1936 Sumner et a1 99 404 x FOREIGN PATENTS ORAPPLICATIONS 485,307 5/1938 Great Britain .Q 99/404 2/1966 Canada 99/40411/1928 Great Britain 99/404 Primary Examiner-Billy J. WilhiteAtt0'rneyStephen S. Townsend et al.

[5 7 ABSTRACT 7 Apparatus for automatically frying potato pieces in ahot oil bath. The apparatus is arranged to receive french fry typepotato pieces, subject the pieces to a pre-determined interval ofcooking in a hot oil bath, thereafter allow the pieces to drain ofexcess hot oil and transfer the drained pieces to a holding basket forsubsequent distribution. A process for automatically preparing frenchfries including the steps of subjecting french fry shaped pieces ofpotato dough to a predetermined term of cooking in a hot oil whiletumbling the pieces to insure uniform contact with the hot oil andthereafter draining any excess oil therefrom I prior to transferring thedrained cooked dough pieces to a holding area.

7 Claims, 8 Drawing Figures 3.776.126 sum 20F 4 PATENTEU DEC 4 I975 FI.G2

PATENTED DEC 4 i973 SHEET 0, 0F 4 FlG 5A AUTOMATIC DEEP FAT FRYER Thisinvention relates to apparatus for automatically and continuously deepfat frying potato pieces such as those in the conventional french frycut form. The invention is particularly suited to the pre-determinedtimed treatment of dried potato product reconstituted as homogeneouspotato dough and shaped into' french fry cut potato pieces by theapparatus disclosed in US. Pat. No. 3,605,647, issued Sept. 29, 1971 orin copending US. Pat. application, Ser. No. 170,164, filed Aug. 9, 1971.The disclosure of the above-identified patent application isincorporated herein by reference for its disclosure of revelantsubjectmatter. The apparatus is equally suited for frying all types offood products, as well as various potato products, suchas french friesmade from raw potatoes or for the finish frying in the frozen state orafter thawing of frozen parfried potatoes made from raw potatoes as wellassimilar products fabricated from potato dough. A

An object of the present invention is to providean improved deep fatfrying device thatemploysa timed.

cycle to automatically convert shaped pieces of recon? stituted potatodough into cooked french fries, thereby enabling a person of onlymoderate skill to operate the device. Apparatus of the type embodyingthepresent invention is arranged to receive a preselected quantity ofshaped potato dough pieces, retain the dough pieces in a heated zone ofcooking oil for a preselected period of time, thereafter drain excesscookingoil from the pieces and remove them from the cooking zone. Theapparatus includes conventional timing circuits so that the foregoingcycle can be repeated as frequently as dough pieces are introduced intothe hot oil zone.

Another object of the present invention is to provide amechanism forremoving the cooked french fry potato pieces from the deep fatfryer-following advance- -ment of the dough pieces through the bath .orhotoil and retention above the hot oil to enable excess oil to drainback into the bath. This object is achieved in part by providing aliquid impervious container into which an open top semi-cylindricalperforate basket'is suspended. In addition, a generally diametrallyextending.

perforate plate is mounted for rotation about'the central axis of thebasket in such a manner that the perforate plate sweeps the dough piecesthroughthehotoil.

Another object of the present invention isto provide a mechanism formoving the reconstituted rfrenchfry shaped potato dough pieces through ahot oil :bath to accomplish the prescribedamount of cooking- This objectis achievedin part by providing apair-ofirotatable perforated rotorbladesadapted to be periodically driven in a timed sequence so as toadvancethezaforementioned potato pieces from the point of gravitationalfeedinput to removal therefrom. A-factor present'in the instantinvention that contributes to the formation of particularly desirablecooked french friedpieces is that the pieces prepared by employing theapparatusof this invention are of uniformly high quality.

It is afurther object of the present invention to prostructure withinwardly sloping walls, dough fines such as crumbs will rapidlygravitate toward the removal valve, with inherent improved separation.The configuration of the crumb valve of this inventionis such that V onbeing opened it provides for the rapid removal of crumb loaded hot oil.I

In another aspect of the invention, heating elements corresponding inlength to the width of the hot oil tank are arranged in an arcuateconfiguration around the semi-cylindrical outer surface of theperforated basket; The hot oil, conventionally maintained at a cookingtemperature of 350F, distributes heat from the. heating elements to thedough pieces. The inwardly sloping walls of the oil-containing tank arepreferably spaced from the perforate basket by distance in? excess ofthe cross sectional dimension of the heatinglelements, but no greaterthan about three times the eross sectional dimension of the heatingelements. The arrangement of heating elements is sufficient to affordoil circulation therearound and to transfer the heat energy from theheating elements to comestibles within the perforated basket. Moreover,this arrangement minimizes the amount- 0f oil required for propercoolingof pieces in the perforate basket.

It is another object of the present invention to provide apparatus thatis easily disassembled and cleaned.

In another aspect of the invention, the activation of the rotor bladesprevents the freely floating dough pieces from sticking together as theyare tumbled during the rotational advancement of the blades during thecooking process. Such tumbling simulates manual shaking, therebyinsuring complete and uniform contact of the hot oil with the surface ofeach french fry body. In a prefered form of the invention there are tworotor blade segments that are radially spaced from the axis of rotationthereof so as to define a space therebetween to enhance oil circulation.Because the inneredges of the rotor blade segments overlap one anotherand because the rotor is driven in only one direction, no comestiblebodies can pass through the space between the blades. i

It is anotherobject of the present invention to provide anapparatuswherein rapid introduction and -removal of the french fry bodies fromthe hot oil bath provides a uniform cooking time. A large portion of thewater evaporated from the french fry pieces is quickly converted intosteam which in bubbling up through the hot oil bath provides theadditional advantage of cleaning and purifying the oil. I

Thus, according to the present invention, a plurality of potato doughpieces are gravitationally deposited in t a cylindrically shaped,perforate basket-immersed in a :tank of hot oil. The potato dough piecesare advanced through and out ,of1he oil bed by the rotation of one of apair of generally diametrically extending perforate plates. Once thecooking step has been completed, the position of the perforate plates isadjusted so that the cooked pieces are retained thereon above the hotoil foran additional brief period of time during which the excess oil isallowed to drain back into the oil bath. Thereafter, the drained, cookeddough pieces are mechanically removed from the perforate plate. Duringthe draining and removal steps, rotational advancement of the perforateplate is temporarily interrupted.

Other objects, features and advantages of thepresent invention will bemore apparent after referringto the following specification andaccompanying drawings in which:

FIG. 1 is a side view of a preferred embodiment with portions brokenaway;

FIG. 2 is'an end view of FIG. 1 with portions broken away;

FIG. 3 is an enlarged cross sectional view of the lower valve assemblyof FIG. 1;

FIG. 4 is an enlarged view of a french unit; and

FIGS. 5A, 5B, 5C and 5D are schematic views depicting the sequentialoperation of the preferred embodiment of FIGS. 1-4.

Referring more particularly to the drawings, a doughcontaining chamber Ahas adjacent the outlet opening thereof a dough cutting mechanism B,illustrated in more detail in FIG. 4. Dough in chamber A is urged towardthe cutting mechanism B, as more fully described in the patentapplication cited hereinabove, from whence it falls through deflectorchute C into automated fryer D.

Referring now to FIG. 4, dough cutting mechanism B is mounted adjacentthe opening in dough-containing chamber A and includes a plurality ofparallel wires 10. The dough separating mechanism B separates the doughinto shaped pieces as the dough is ejected from doug-containing chamberA. For sealing chamber A during introduction of the dough constituentsthereinto and during the time required for the constituents to set intoa relatively firm dough, as more fully described in the patentapplication cited herein-above, a seal plate 12 is provided. This sealplate 12 moves toward and away from the open end of chamber A when sealplate operating rod 14 is activated. The inner face of seal plate 12 ispreferably resilient so as to afford a watertight seal. A suitablearrangement is the provision of a resilient annular insert or ring 16along the inner surface of seal plate 12. A cylindrical frame 18 has anouter edge congruent to resilient annular ring 16, so that when the sealplate is in a closed position, chamber A is sealed.

Cylindrical frame 18 is suitably. retained in position on the end ofchamber A and carries wires in spanning relation of the opening ofchamber A. Seal plate 12 is supported at its approximate center by arm20, which arm is carried on the outer end of seal plate operating rod14. Operating rod 14 is supported exterior of chamber A for movementalong an axial path parallel to the central axis of chamber-A in amanner more fully described in the patent application cited hereinabove.

Transverse dough cutter 22 is disposed to swing back and forth so as toseparate into french fry shaped bodies the dough portions protrudingbeyond wires 10. The transverse dough cutter is mounted on a pivot shaft(not shown) for movement about an axis that is generally verticallyaligned above the central axis of chamber A. Transverse cutter 22includes an arm 24 that is mounted rigidly to the pivot shaft. To thefree end of arm 24, a releasable connector 26 mounts a cutter frame 28to the arm. From arm 24, fingers 30 and 32 (shown on FIG. I) extendinwardly toward the wires 18. Spanning the inner end of fingers 30 and32 is a single taunt wire 34 that separates that portion of the doughthat protrudes from chamber A through the spaces between wires 18, whenit is advanced across the ejected dough.

fry forming As is shown schematically in FIG. 5A, french fry bodies Eare separated from the dough mass protruding from chamber A and fall bygravity into and through french fry deflector chute C. As seen mostclearly in FIGS. 1 and 2, deflector chute C includes a rectangular crosssectional opening and is of substantially greater width than thediameter of chamber A. The lowermost side 36 of chute C is formed so asto provide a plurality of elongated openings 38 that allow for theseparation of crumbs or other small dough particles from the french frybodies being formed by dough cutting mechanism B. Near the egress ofchute C and integral with the internal surface of side 36 is bull nose40 of triangular cross section for diverting the french fry bodies Efalling generally down the center of chute C toward the outermost edgesof chute C so that more uniform distribution within fryer D isaccomplished.

Automatic fryer D comprises an outer liquid impervious tank 42 includinginwardly sloping walls 43 extending to a lower end defined by crumbvalve Fdescribed in more detail hereinafter with reference to FIG. 3.Disposed within open top liquid impervious container (tank) 42 is adrum-shaped basket 44 having a perforate cylindric wall 45 extending inexcess of 180 therearound to an open top. Disposed below basket 44 andgenerally tangential to the outer surface of basket 44 are a pluralityof heating elements 46. Supported in slots 47 formed in the end walls ofbrasket 44 and mounted for rotation within basket 44 is a generallydiametrally extending blade assembly 48 having imperforate ends 50 forproviding rigidity to perforate rotor blades 52A and 52B. Rotor blades52A and 52B are mounted on axis 54 that is supported by basket 44 inslots 47. Axis 54 extends beyond the extremes of basket 44 at one end 56for a distance sufficient for attachment of pulley 58. As shown mostclearly in FIG. 1, pulley 58 is in driving engagement with pulley 60through belt 62 for advancing assembly 48 counterclockwise with respectto FIG. 1. Pulley 60 is driven from a power source (not shown) andcontrolled by conventional timing circuits (also not shown).

Although french fry bodies E are gravitationally fed to fryer D, removaltherefrom involves both mechanical advancement of blade assembly 48 andsynchronized activation of perforate plate assembly 64. Plate assembly64 includes perforate plate 65 mounted on axis 66 for reciprocalmovement tangential with respect to axis 54 about which blades 52A and52B are rotated. Plate 65 is driven about axis 66 through pivotallyengaged linking members 68, 68 and 68" which are in turn driven by therotation of wheel 70. .Wheel 70 in turn is rotatably driven from a powersource not shown. Suitable conventional timing circuits (not shown) areprovided to-provide the interaction of rotor blade assembly 48 withplate assembly 64 when potato dough bodies E are released from cuttingmechanism B and gravitationally descend through deflector chute C.

Referring now to FIG. 3, liquid impervious container 42 includes acircular opening 72 formed at the lowermost portion thereof whereininwardly sloping sides 43 converge. Sides 43 are provided with acircular flange 74 surrounding opening 72 and against which valve 76 isadapted to abut in fluid-tight engagement. Conically shaped abut-offvalve 76 includes O-ring 78, formed of a pliable material such asteflon, for accomplishing liquid impervious engagement with circularflange 74 when advanced into contact therewith. Advancement andwithdrawal of valve 76 from engagement with flange 74 is accomplished byadvancing or retracting, respectively, threaded shaft 80 which in turncauses lever arm 82 to pivot about its fulcrum 84. Blades 52A and 52B,plate 65 and the cylindrical surface 45 of drum-shaped basket 44 are alladvantageously formed of 18 gauge stainless steel with one-fourth inchdiameter perforations staggered on three-eighths inch centers. Suchperforations maximize oil retention and return thereof to the bath,thereby extending the useful life of the oil and minimizing waste. Rotorblades 52A and 52B are preferably arranged to provide a onesixteenthinch clearance between their outer ends and the internal surface ofperforated wall 45. Similarly, plate 65 is formed to provide slightclearance with the french fry body bearing surface of either blade 52Aor 523 when positioned for interaction with plate 65.

Turning now to schematic drawings 5A, 5B, 5C and 5D, to illustrate theoperation of the apparatus of this invention, dough containing chamber Aand cutting mechanism B are activated to provide dough bodies E to fryerD. Perforate blade 52A is maintained in alignment with the lowermostside 36 of the rectangular opening in deflector chute C so as to guidefrench fry bodies E into basket 44 filled with hot oil having an uppersurface level 86 (FIG. 5A). Perforate blade 52A is then rotatablyadvanced approximately 90 (or 450) and thereafter temporarily stoppedwhile the cooking of french fry bodies E from a previous batch iscompleted, as illustrated in FIG. 5B. Perforate blade 52A is thenadvanced approximately an additional 30 so as to advance french frybodies E' to a location above the surface 86 of the hot oil where thefrench fry pieces are allowed to drain substantially free of excess oil.Of course, while french fry bodies E are being drained of excess oil,french fry bodies E remain in the hot oil bath and are subjected toadditional cooking.

Once the draining operation has been completed, plate 65 is advancedtangential to the concave surface of perforate blade 52A to sweep frenchfry bodies E into holding basket 71. The device of this invention isformed so that the pivot point 66 for plate 65 coincides with the centerof curvature of the concave surface of both of perforate blades 52A and523, so that the reciprocal movement of plate 65 will at all times beuniformly spaced relative to the surface of the perforate blades (andgenerally tangential thereto) to insure that all french fry bodies areremoved. As shown in FIG. 5D, once bodies E are removed from blade 52A,plate 65 is returned to its inoperative position and the perforateblades are again rotatably advanced to the position corresponding toFIG. 5A to allow for the introduction of a subsequent batch of frenchfry bodies E".

In a typical cycle, blades 52A and 52B are retained in the positionshown in FIG. 5A for a period of approximately 5 seconds while dough isdispensed from chamber A through cutting mechanism B and allowed to dropthrough deflector chute C into the hot oil. Pulley 60 is then energizedto advance blades 52A and 52B through one and one quarter revolutions(at arate of approximately 12 seconds per revolution). This tumbling,cooking step requires 15 seconds, wherein baffle blades 52A and 52Breach the position illustrated by schematic FIG. 53. Cooking isthereafter continued for an additional 12 seconds while blades 52A and52B remain stationary. Pulley 60 is then activated for 2 secends to movethe paddles approximately 30 to the unloading position where the centerof curvature of blade 52A coincides with the pivot point of plate 65.The french fries are then allowed to drain for 4 seconds and thereafterswept ahead of plate 65 into holding basket 71, an action requiringapproximately 6 additional seconds. Then blade 52A is returned to theoriginal position illustrated by FIG. 5A wherein further french friesare introduced for sequential treatment.

What is claimed is:

1. Apparatus for deep frying comestible bodies comprising means definingan open top liquid impervious container, a basket disposed in saidcontainer, said basket having a perforate cylindric wall extending morethan and having an open top, a generally diame-. trally extendingperforate plate mounted in said basket for rotation about the centralaxis of said cylindric wall, said plate being of a width so that theopposite outer edges thereof are adapted to be spaced from the cylindricwall of said basket by a distance less than the minimum dimension ofsaid bodies, said plate defining first and second generallysemi-cylindrical compartments within said basket which compartments movein response to rotation of said plate, means for rotating said plate tomove said compartments sequentially into and out of communication withthe open top of said basket, means operatively connected to said platerotating means for stopping said plate in a loading position at Y whichsaid first compartment registers with said open top to affordintroduction of comestibles thereinto, and

means active after introduction of comestibles into said firstcompartment to activate said plate rotating means so as to movesaidplate through more than one revolution to a generally horizontalposition in said basket so that said first compartment is below saidplate.

2. Apparatus according to claim 1 wherein said plate includes twoarcuate segments that extend generally radially of said central axis,said segments being concave in the direction of rotation'thereof, saidsegments having a radius of curvature about a point exterior of saidbasket when in alignment with said open top, and means mounted forpivotal movement about said point for sweeping comestibles from saidbasket when each said segment resides in concentricity of said point.

3. Apparatus according to claim 1 wherein said liquid imperviouscontainer defining means includes a generally vertical front wall, agenerally vertical rear wall parallel to said front wall and spacedtherefrom by a distance greater than the diameter of said basket, a pairof generally vertical end walls spanning the ends of said front and rearwalls, and a bottom wall having portions that slope from the lowerextremities of said front, rear, and sidewalls downward and inwardtoward a site at which is defined a drain opening, and means for closingsaid drain opening.

4. Apparatus in accordance with claim 3 wherein said drain opening is ofcircular configuration and said drain closing means includes a conicallyshaped 'valve adapted to abut said opening when in a closed position.

5. Apparatus in accordance with claim 4 and further characterized by alever arm adapted to cooperate with said valve to advance and retractsaid valve with respect to said drain opening.

6. Apparatus in accordance with claim 1 and further characterized byheating elements disposed within said liquid impervious containertangential to the perforate cylindric wall of said basket.

7. Apparatus in accordance with claim 6 wherein said heating elementsare spaced from said-perforate basket by a distance in excess of thecross sectional dimension of the heating elements but less than aboutthree times the cross sectional dimension of the heating elements.

4 t r a 0:

1. Apparatus for deep frying comestible bodies comprising means definingan open top liquid impervious container, a basket disposed in saidcontainer, said basket having a perforate cylindric wall extending morethan 180* and having an open top, a generally diametrally extendingperforate plate mounted in said basket for rotation about the centralaxis of said cylindric wall, said plate beIng of a width so that theopposite outer edges thereof are adapted to be spaced from the cylindricwall of said basket by a distance less than the minimum dimension ofsaid bodies, said plate defining first and second generallysemicylindrical compartments within said basket which compartments movein response to rotation of said plate, means for rotating said plate tomove said compartments sequentially into and out of communication withthe open top of said basket, means operatively connected to said platerotating means for stopping said plate in a loading position at whichsaid first compartment registers with said open top to affordintroduction of comestibles thereinto, and means active afterintroduction of comestibles into said first compartment to activate saidplate rotating means so as to move said plate through more than onerevolution to a generally horizontal position in said basket so thatsaid first compartment is below said plate.
 2. Apparatus according toclaim 1 wherein said plate includes two arcuate segments that extendgenerally radially of said central axis, said segments being concave inthe direction of rotation thereof, said segments having a radius ofcurvature about a point exterior of said basket when in alignment withsaid open top, and means mounted for pivotal movement about said pointfor sweeping comestibles from said basket when each said segment residesin concentricity of said point.
 3. Apparatus according to claim 1wherein said liquid impervious container defining means includes agenerally vertical front wall, a generally vertical rear wall parallelto said front wall and spaced therefrom by a distance greater than thediameter of said basket, a pair of generally vertical end walls spanningthe ends of said front and rear walls, and a bottom wall having portionsthat slope from the lower extremities of said front, rear, and sidewalls downward and inward toward a site at which is defined a drainopening, and means for closing said drain opening.
 4. Apparatus inaccordance with claim 3 wherein said drain opening is of circularconfiguration and said drain closing means includes a conically shapedvalve adapted to abut said opening when in a closed position. 5.Apparatus in accordance with claim 4 and further characterized by alever arm adapted to cooperate with said valve to advance and retractsaid valve with respect to said drain opening.
 6. Apparatus inaccordance with claim 1 and further characterized by heating elementsdisposed within said liquid impervious container tangential to theperforate cylindric wall of said basket.
 7. Apparatus in accordance withclaim 6 wherein said heating elements are spaced from said perforatebasket by a distance in excess of the cross sectional dimension of theheating elements but less than about three times the cross sectionaldimension of the heating elements.